This invention generally relates to navigation or route guidance systems that can be tailored to a user""s particular wishes.
Navigation systems generally provide a recommended route from a starting point to a desired destination. Generally the starting point and desired destination are selected from a large database of roads stored in a mass media storage, such as a CD ROM, which includes the roads in the area to be traveled by the user. The navigation system can be located in a personal computer or can be installed in a vehicle. If the navigation system is installed in a vehicle, the starting point is typically the current position of the vehicle, which can be input from an associated positioning determining device, such as a GPS (Global Positioning System) receiver.
The navigation system determines a route from the starting point to the destination utilizing an algorithm well-known to those in the art and currently in use in many navigation systems. Usually there are many potential routes between the selected starting point and the desired destination. The navigation system selects a recommended route based upon certain xe2x80x9ccostxe2x80x9d values associated with each segment of road in the road database. These cost values include the length of the road segment and the estimated time of travel through the road segment. The navigation system selects the potential route with the lowest total cost to be the recommended route. Depending upon the predetermined algorithm of the navigation system, the navigation system will recommend the route with the shortest total length, the lowest total time, or some weighted average of length and time.
The recommended route is then displayed to the user as a map showing the starting point and desired destination and highlighting the recommended route. Preferably, if the navigation system is installed in a vehicle, the navigation system displays the current position of the vehicle and turn-by-turn instructions to the driver, guiding the driver to the selected destination.
Some drivers prefer to completely avoid certain roads at certain times due to personal preferences, construction delays, traffic congestion or because they believe certain areas to be unsafe.
A current navigation system has several limitations on how it selects a potential route as the recommended route. The known navigation system permits the driver to select a preference such as fastest route; shortest route; use highways; avoid highways; or adjust a weighing factor to be given to these preferences. The known current system requires the user to adjust the weighing factor for each preference individually for each segment of a road, a time consuming task. In addition, the known navigation system universally applies a selected preference, for example, use highways irrespective of the other cost factors such as time of travel. Finally, the current navigation system does not permit a user to designate specific times during which they wish to avoid certain road segments.
Thus, it is desirable to provide a method and a system that permits a user to rapidly designate road segments to be excluded from recommended route determinations during certain times. It is also desirable to provide such a method and system that permits the excluded road segments to be associated with a specific user. Finally, it is desirable to permit a user to designate road segments to be excluded on a system that is separate from the navigation system.
The present invention provides a method for modifying a database of road segments of a navigation system which permits the user to designate certain road segments to be avoided when planning a route. The method comprises the steps of providing a database of road segments to be traveled by a user. A map of a plurality of the road segments is displayed on a display. An input device is used to encircle and select at least one of the road segments on the display. A cost, such as estimated time of travel across that road segment or estimated length of travel across that road segment, is associated with each road segment and selecting a road segment increases the cost of the selected road segment. The selected road segment is thus most likely to be excluded from a subsequent route determination from the database of roads between a beginning point and a destination point that could include the selected road segment.
The system of the present invention comprises a route exclusion list system having a database containing a plurality of road segments to be traveled by a user, wherein the database includes a cost associated with each of the road segments. A display displays a map of a plurality of the road segments. An input device permits a user to encircle and select at least one of the road segments on the map. An exclusion system increases the cost of the selected road segment.
The route exclusion list system permits a user to designate large areas of a map rapidly and the route exclusion list system can be operated on a personal computer apart from the navigation system itself. The selected road segments and their associated increased costs can be communicated to the navigation system after the road segments have been selected. In addition, the route exclusion list system permits a user to designate certain times during which the user wishes the cost of a selected road segment to be increased.
These and other features and advantages of this invention will become more apparent to those skilled in the art from the following detailed description of the presently preferred embodiment. The drawings that accompany the detailed description can be described as follows.